docstr: Read PID info from file.
docstr_tok: ["Read","PID","info","from","file","."]
code: def load_pid_file(filepath: str, port: int = None):
      """
      Read PID info from file.
      """
      if port is None:
          port = os.path.basename(filepath).split(".")[0].split("_")[1]
      if not os.path.exists(filepath):
          log.logger.error(
              "PaddleHub Serving config file is not exists, please confirm the port [%s] you specified is correct."
              % port
          )
          return False
      with open(filepath, "r") as fp:
          info = json.load(fp)
          return info
  
imports: import argparse
  import os
  import platform
  import json
  import multiprocessing
  import time
  import signal
  import paddlehub
  from paddlehub.commands import register
  from paddlehub.serving import app_compat
  from paddlehub.env import CONF_HOME
  from paddlehub.serving.http_server import run_all, StandaloneApplication
  from paddlehub.utils import log
  from paddlehub.utils.utils import is_port_occupied
  from paddlehub.server.server import CacheUpdater
label_desc: Use image node_id 2 for calling the ServingCommand obj's underlying member method code with example usage: obj.load_pid_file(filepath, port) and returns: False, info